Few MPs would have worked harder to defend their seats at this election than Environment Minister Malcolm Turnbull, whose blue ribbon Sydney seat of Wentworth is under siege not just from Labor but a range of environmental activists, mostly coalescing around the Greens.

But in the second week of the campaign, Mr Turnbull found the time to announce that the Government, already in caretaker mode, would bankroll to the tune of $10 million the investigation of an untried Russian technology that aims to trigger rainfall from the atmosphere, even when there are no clouds.

It is a decision that raised the eyebrows of water experts around the country.

Mr Turnbull's office says there was no breach of caretaker protocol because the project was actually approved before the election was announced.

The money bankrolls research into a mysterious ionisation technology promoted by the Australian Rain Corporation.

And a commercial trial by a wastewater centre at Queensland University left independent experts like Emeritus Professor Neville Fletcher of the Australian National University a little unconvinced.

"I think the conclusion was, and I might even quote that it said: 'There is no evidence to show that the technology does not work'," Professor Fletcher told The 7.30 Report.

"Now that's a little bit negative. So I don't know. I thought that that was - inconclusive is about where I'd put it."

Rainmaker Ian Searle, the father of cloud seeding in Australia for the Tasmanian Hydro scheme, has also expressed doubts, as has Israel's internationally respected cloud physicist Professor Daniel Rosenfeld.

"There is no single scientific paper, only the patent, and one can patent anything claiming it's to do anything that he likes, as long as no one else has made the same claims before," Professor Rosenfeld said.

Mr Searle says all the literature he has seen on the technology shows it to be a bogus science.

"The one that is being touted at the moment sounds very similar to a group in the USA called the Cloudbusters, and they're supposed to ionise the atmosphere in order to make clouds out of blue skies and then to produce rain from those clouds," he said.

Electrification of the ionosphere to create clouds out of thin air. Certainly sounds a lot like the secret Australian rain device - no photographs allowed - that so excited the Minister and those who will share his six-month $10 million research funding.

All for a company the minister says is Australian-owned. Although the 7.30 Report found it is actually 75 per cent Swiss-owned.

Requests for interviews with Mr Turnbull, the head of the Australian Rain Corporation, the head of the centre contracted to test the device were declined.

So, too, the head of the National Water Commission, which insisted on a presentation of the technology for local physicists.

The Rain Corporation presented research documents written in Russian, explained by a Russian researcher who spoke to local experts in Russian.

"It's kind of difficult, because he didn't speak English or understand English, so we didn't get a lot of information there, and as I said, such written information as they had was all in Russian. So couldn't get anything out of that," Professor Fletcher said.

The physicists recommended more scientific work be done at no great expense before proceeding with any trial, which may then be worthwhile, they said.

But Mr Turnbull decided the trial should proceed and authorised a $10 million payment.

Mr Searle says he is astonished the National Water Commission allowed it to pass.

It's true that in the largely blue ribbon seat of Wentworth in Sydney's east, Mr Turnbull is struggling for re-election, though struggling might not be the right word. He does have a distinct advantage.

Murdoch's nephew

Emanating from affluent suburbs like Vaucluse, Rose Bay and Watson's Bay, Malcolm Turnbull's fundraising group the Wentworth Forum, includes a long list of generous donors including Frank Lowy, Ros Packer, John Simons, and Matt Handbury, chairman and part-owner of the so-called Australian Rain Corporation, beneficiary of the Minister's funding.

Businessman Geoffrey Cousins says he has never seen the weight of spending in any one seat that Mr Turnbull is putting out in Wentworth.

"It must be well over $1 million just in this one seat, and in Australia, that's an extraordinary amount of money. I mean, it's starting to get like the American elections," he said.

Mr Handbury is the wealthy nephew of Rupert Murdoch and chairman and proprietor of Murdoch Books, which is the headquarters for Australian Rain Corporation.

The 7.30 Report put to Malcolm Turnbull the following questions: has Matt Handbury's contribution to your fundraising Wentworth Forum helped in securing funding for the Australian Rain Corporation?

"There is absolutely no connection," he said "That is an outrageous suggestion".

Secondly, why couldn't the Matt Handbury Swiss consortium pay for its own research?

Response: "The company is contributing funding to the research and trial."

Our final question to the Minister was why should this not be seen as securing funding for one of your electorate supporters ahead of an election the Government is tipped to lose?

Mr Turnbull did not directly answer this question, suggesting perhaps his first answer had.

"The Australian Government is open to new and innovative approaches to secure water," he said.

Doubts on cloud seeding

Previously Mr Turnbull was dubious about the practice of rain enhancement by aerial seeding clouds with salt particles to help rain drops form.

In a six-year $20 million State Government trial, 20 per cent federally funded, the Snowy Hydro Scheme has been experimenting with cloud-seeding burners mounted on mountain tops.

Cloud seeding is regarded as an effective method for increasing snowfall, but Mr Turnbull's March press release raised doubts, stating:

"Cloud seeding is effective only in a limited number of weather conditions... It requires existing clouds. It will not produce rain out of thin air... An American research institute concluded there was no conclusive scientific proof that cloud seeding works."

Mr Searle disagrees.

"In Tasmania the results have been highly favourable from the beginning. We've been going since 1964," he said.

A respected world expert on cloud physics at the Hebrew University of Jerusalem, Professor Rosenfeld believes pollution particles are inhibiting rainfall over Australia's most populated areas and beyond.

More specialised cloud seeding could help, he says, if only it could win the support of Australia's Environment Minister, who the Israeli says has instead directed scarce funding from the Australian water fund to Mr Handbury's corporation.

The local representative of the Israeli cloud seeding project in Australia is Aron Gingis.

"When I brought it to the attention of Ken Matthews, chief executive officer of National Water Commission, well, if you're giving this company this kind of serious money, why couldn't we apply?" he said.

"And then he suggested clearly to me that, 'Look, it's no point applying because Australian water fund had been expended'.

"In other words, the money had been spent. So when I argue with him - not argued but suggested to him, well, if the money was spent, where did you find this $11 million?

"And he suggested to me clearly that this money was especially allocated to the National Water Commission by Minister Turnbull, a special allocation for this specific project. And to me it sounds, you know, bewildering."

He said $11 million could produce a lot of rain through cloud seeding.

"You could say that his decision wasn't influenced by the association of Matt Handbury with Wentworth Forum, I don't believe it. It's my opinion," he said.

There is a lot riding on this $10 million bet by Mr Turnbull.

If he can silence the sceptics and make it rain, even when there are no clouds on the horizon, he will be hailed as a visionary and a hero.

If it is found the sceptics are right and this technology does not work, the thunder will reverberate across the country.

"If he claims that the conventional method is unproven technology, so much more so he should be very careful with the really baseless technology," Professor Rosenfeld said.

"Frankly, I was astonished to go for something that is quite unproven, quite untried, and you could do wonderful things with that money," Mr Searle said.